<p>Normalized maximal fluorescence intensity of cT1R1-NTD before and after addition of ligands (100 μM final concentration). L-Cys does not affect cT1R1-NTD fluorescence. Fluorescence of cT1R1-NTD alone was defined as 100% in absence of ligand. Excitation and emission wavelength were 295 nm and 340 nm, respectively. cT1R1-NTD concentration was 0.5 μM. Data values are the mean ± SEMs of more than nine independent replicates of at least three independently refolded protein samples. *, Significantly different from cT1R1-NTD before addition of ligands (one-way ANOVA followed by Dunnett’s, p ≤ 0.05; for L-Arg p ≤ 0.08).</p
